\begin{tikzpicture}
    \tkzDefPoints{0/0/O, 4/0/C}
    \tkzDefPoint(30:3.5){A}
    \tkzDefPoint(-30:3.5){B}
    \tkzDefPointOnLine[pos=0.8](O,C)  \tkzGetPoint{P}
    \tkzDefLine[altitude](O,P,A)  \tkzGetPoint{D}
    \tkzDefLine[altitude](O,P,B)  \tkzGetPoint{E}

    \tkzDrawSegments(O,A  O,B  O,C  P,D  P,E)
    \tkzMarkRightAngle(P,D,O)
    \tkzMarkRightAngle(P,E,O)
    \tkzLabelPoints[left](O)
    \tkzLabelPoints[above left](D)
    \tkzLabelPoints[above](A)
    \tkzLabelPoints[below](B)
    \tkzLabelPoints[below, xshift=0.3em](P)
    \tkzLabelPoints[below left](E)
    \tkzLabelPoints[above](C)
\end{tikzpicture}

